HDF files within the PyCBC workflow¶
Note
Format specifications are provided here to aid in development. The canonical definition, as always, lives within the code itself.
single inspiral triggers¶
Executables¶
- pycbc_inspiral
Specification¶
All keys in the inspiral output are prefixed with the IFO name, e.g. H1, L1. Currently, only a single ifo is present in each file, but at a future date, multiple may be allowed.
The following table consists of columns of trigger data. Each column is of the same length and an index into one column corresponds to the same trigger in each of the other columns.
| path | description |
|---|---|
| IFO/snr | The mangitude of the complex SNR |
| IFO/coa_phase | The phase of the complex SNR |
| IFO/end_time | The gps time of the trigger |
| IFO/chisq | Value of the bruce power chisq |
| IFO/chisq_dof | Not DOF. The number of bins in the chisq. DOF = 2 * (num_bins -1) |
| IFO/bank_chisq | Value of the bank chisq |
| IFO/bank_chisq_dof | Number of templates used to construct the bank chisq |
| IFO/cont_chisq | Value of the autochisq |
| IFO/cont_chisq_dof | Number of dof for the auto chisq |
| IFO/template_duration | Duration of the template approximant used for this trigger |
| IFO/sigmasq | The weighted power of the template, placed at 1Mpc, used for this trigger |
| path | description |
|---|---|
| IFO/search/start_time | Array of gps times which denote the start of a valid period of triggers |
| IFO/search/end_time | Array of gps times which denote the corresponding end of a vlid period of triggers |
The following are columns that exists in the file, but should not be used by any user. Its definition or existence is subject to change without notice.
| path |
|---|
| IFO/template_hash |
combined single inspiral triggers¶
Executables¶
- pycbc_coinc_mergetrigs
Specification¶
All keys in the inspiral output are prefixed with the IFO name, e.g. H1, L1. Currently, only a single ifo is present in each file, but at a future date, multiple may be allowed.
The following table consists of columns of trigger data. Each column is of the same length and an index into one column corresponds to the same trigger in each of the other columns.
| path | description |
|---|---|
| IFO/snr | The mangitude of the complex SNR |
| IFO/coa_phase | The phase of the complex SNR |
| IFO/end_time | The gps time of the trigger |
| IFO/chisq | Value of the bruce power chisq |
| IFO/chisq_dof | Not DOF. The number of bins in the chisq. DOF = 2 * (num_bins -1) |
| IFO/bank_chisq | Value of the bank chisq |
| IFO/bank_chisq_dof | Number of templates used to construct the bank chisq |
| IFO/cont_chisq | Value of the autochisq |
| IFO/cont_chisq_dof | Number of dof for the auto chisq |
| IFO/template_duration | Duration of the template approximant used for this trigger |
| IFO/sigmasq | The weighted power of the template, placed at 1Mpc, used for this trigger |
| IFO/template_id | The unique template id value. This is the index into the hdf template file format |
The key feature that the combined trigger format adds is the convenience of precalculated region references to access only the data produced by a given template. These values are stored in region reference arrays. The length of each array is the same as the number of templates, and an index into the array matches the template_id number. Each array directly maps to a single column.
| path |
|---|
| IFO/bank_chisq_dof_template |
| IFO/bank_chisq_template |
| IFO/chisq_dof_template |
| IFO/chisq_template |
| IFO/coa_phase_template |
| IFO/cont_chisq_dof_template |
| IFO/cont_chisq_template |
| IFO/end_time_template |
| IFO/sigmasq_template |
| IFO/snr_template |
| IFO/template_boundaries |
| IFO/template_duration_template |
| path | description |
|---|---|
| IFO/search/start_time | Array of gps times which denote the start of a valid period of triggers |
| IFO/search/end_time | Array of gps times which denote the corresponding end of a vlid period of triggers |
Example uses¶
Accessing triggers by template
import h5py
f = h5py.File('H1-testdata.hdf')
snr_regs = f['H1/snr_template']
snr_template_0 = f['H1/snr'][snr_regs[0]]